Principles - Upper GI System

Question 1

What is the upper GI tract?

Answer 1

Oral cavity 
Oropharynx 
Laryngopharynx 
Oesophagus 
Stomach 
Small Intestines

Question 2

Where does jaw opening and closing occur?

Answer 2

At the right and left TMJs (temporomandibular joints)
Synovial joints between mandibular fossa and articular tubercle of the temporal bone and the head of the condylar process of the mandible

Question 3

What are the muscles of mastication?

Answer 3

Masseter
Temporalis
medial pterygoid
lateral pterygoid

Question 4

Which muscle prevents dribbling?

Answer 4

The orbicularis oris

Circularly arranged around the lips - contraction draws the lips together

Question 5

Where are the upper/lower dental arches contained?

Answer 5

Upper - maxilla

Lower - mandible

Question 6

What is the correct name for the gums?

Answer 6

Gingivae

Question 7

Which areas of the oral cavity have surface keratin?

Answer 7

Gingivae and hard palate - for their protection during chewing

Question 8

Describe the mucosa of the oral cavity.

Answer 8

Covered with stratified squamous epithelium

Question 9

What bones make up the hard palate?

Answer 9

The maxilla and the palatine bone

Question 10

What are the features associated with the soft palate?

Answer 10

Palatine tonsil - sits between the arches of the soft palate
Uvula - 2 of the soft palate muscles sit within this, hangs down at the back of the oral cavity

Question 11

What is the special sensation of the oral cavity?

Answer 11

Taste

Question 12

What are papillae? What are their different functions?

Answer 12

Finger-like structures on the dorsum of the tongue
Some give the surface texture and help the tongue manipulate food
Others are concerned with taste

Question 13

Where/what is the posterior 1/3rd of the tongue?

Answer 13

The vertical part of the tongue

Not in the oral cavity - in the oropharynx

Question 14

What papilla have taste buds?

Answer 14

Foliate papillae (most posterior)
Vallate papillae
Fungiform papillae

Question 15

What papilla don’t have taste buds?

Answer 15

Filiform papillae (most anterior)

Question 16

How is the tongue suspended in the oral cavity?

Answer 16

There are 4 pairs of extrinsic muscles of the tongue
Originate external to the tongue and insert into it
Move the tongue around during mastication, speech and swallowing

Question 17

How is the shape of the tongue modified?

Answer 17

There are 4 pairs of skeletal intrinsic muscles of the tongue
Modify the shape of the tongue during function e.g. rolling

Question 18

What is the buccinator? What does it do?

Answer 18

This is the muscle of the cheeks
With the help of the tongue, the buccinator acts to position the food bolus between the occlusal surfaces of the teeth for mastication

Question 19

How many teeth should there be in the adult mouth?

Answer 19

32

Question 20

What is the occlusion?

Answer 20

The bite

How the occlusal/biting surfaces of the upper and lower teeth fit together

Question 21

What does saliva contain?

Answer 21

99% water
Mucin (lubricant) - aids swallowing and speech, keeps mucosa moist, buffer for plaque acids and also contains antimicrobial elements and amylase to begin CHO digestion

Question 22

What are the major salivary glands?

Answer 22

Parotid - near the ear
Submandibular - under the mandible
Sublingual - under the tongue

Question 23

What are the minor salivary glands for?

Answer 23

Basal secretion - background and continuous secretion of saliva to keep the mouth moist

Question 24

Where do the salivary glands empty?

Answer 24

Parotid duct - inner surface of the cheek, usually opposite the maxillary second molar
Sublingual duct - under the tongue
Submandibular duct - the floor of mouth on both sides of the tongue frenulum at sublingual caruncula

Question 25

What is the pharynx?

Answer 25

The throat
A muscular ‘incomplete tube’ lined with non-keratinised stratified squamous epithelium
Tonsils are contained here

Question 26

What are the three parts of the pharynx?

Answer 26

Nasopharynx - posterior to nasal cavities
Oropharynx - posterior to oral cavity
Laryngopharynx - posterior to larynx, in-between epiglottis and oesophagus

Question 27

What is Waldeyer’s ring?

Answer 27

Ring of tonsils

Arrangement of tonsils in the pharynx

Question 28

What do the uvula and epiglottis do together?

Answer 28

Guide the food bolus away from the midline laryngeal inlet, so food isn’t aspirated

Question 29

What/where are the longitudinal muscles of the pharynx?

Answer 29

Inner vertically arranged layer
Attach inferiorly to the larynx
contract during swallowing to shorten the pharynx, reducing bolus transit time
Contraction also raises the larynx towards the epiglottis, closing the laryngeal inlet

Question 30

What/where are the constrictor muscles of the pharynx?

Answer 30

Outer, circularly arranged layer
Superior, middle and inferior
Contract sequentially from superior to inferior to push the food bolus inferiorly into the oesophagus

Question 31

What is the oesophagus?

Answer 31

The inferior continuation of the laryngopharynx

Question 32

Where is the oesophagus?

Answer 32

Lies posterior to the trachea

Question 33

What is the structure of the oesophagus?

Answer 33

Muscular tube
Muscle type gradually transitions from skeletal proximally to smooth distally
Lined internally with non keratinised stratified squamous mucosa